﻿<!DOCTYPE html>
<html>
	<meta charset="UTF-8"/>
	<head>
		<script>
			//数据类型的种类:
			
			var abc = 999;
			
			document.write(typeof abc); //number
			
			
			document.write("<br>");
			
			var a2 = "abc";
			
			document.write(typeof a2); //string
			
			var a3 = true;  //布尔类型
			
			document.write("<br>");
			
			document.write(typeof a3); //boolean
			
			var a4;
			document.write("<br>");
			
			document.write(typeof a4); //undefined
			
			var a5 = new Object();
			document.write("<br>");
			
			document.write(typeof a5); //object
			
			var a6 = function(){};
			document.write("<br>");
			
			document.write(typeof a6); //function
			
			var a7 = null;
			document.write("<br>");
			
			document.write(typeof a7); //object
			
			
			
			
			
		</script>
	</head>
	<body>
		
	</body>
</html>











